Telephone



(No Model.)

J. R., J. D. 8v C. F, HOLCOMB. Telephone.

No. 240,713. Patented l\pril'26,1881.v

MJC

WIT'NESSES N. PETERS, PHOTD-LITMDGRAFHER. wAsHINGTcN. D Cvv UNITEDSTATES PATENT OFFICE.

JAMES R. HOLOOMB, JOHN D. HOLOOMB, AND CHARLES F. HOLOOMB, OF MALLETCREEK, OHIO.

TELEPHONE.

SPECIFICATION forming part of Letters Patent No. 240,713, dated April26, 1881.

Application filed February 19, 1881.

To all whom it may concern:

Be it known that we, JAMES R. HOLOOME, JOHN D. HOLOOME, and CEAELEs F.HOL- COMB, citizens of the United States, residents at Mallet Greek, inthe county Ot' Medina and State of Ohio, have invented certain new anduseful Improvements in Telephones; and we do hereby declare thefollowing to be a full, clear, and exact description ot' the invention,such as will enable Others skilled in the art to which it appertains tomake and use the same, reference being had to the accompanying' drawings, and to letters or figures of reference marked thereon, which forma part ot' this specification, in which- Figure 1 is a front view. Fig.2is an inside view. Fig. 3 is a cross-section ot' the device. Fig. 4 is aView of the insulator. l

'lhis invention relates to telephones of the class known as mechanicaL77The object otthe invention is to obtain a very sensitive and powerfultelephone combining ioudness and clearness with freedom from the lateralringing vibrations so common in telephones ot' this class.

To this end the invention consists in the construction hereinafterdescribed.

In the annexed drawings, A is a box, made Ot' light sonorous wood orother equivalent material, to add to the power ot' the voice by theresonance.

ais the outer face of the box, back of which is located thediaphragm-receiving board l.

a is a circular Opening in face a, and I) "is another, registeringtherewith in board B.

O C are the diaphragms, which are fastened by their edges c c', one tothe inside, the other to the outside, of board B, said diaphragms beingstretched across Openin g b, having an air-space, z, between them, beingheld apart at their centers by a small button, n, and having thecOncavO-convex shape shown.

D is the line-wire, having loop d, and passing through the diaphragms CC at their centers, and connected to the call-button E at the outside.By striking on this button the diaphragms are vibrated, which vibrationswill be communicated to the receiver at the end of the line and give analarm.

(No model.)

F F are two wires, crossing` each other and attached to the line-wire Dat loop d. The endsfof these wires are attached to the slidingcross-bars G G, which areregulated by the screws H, by which they may bedrawn in and out, by which means the diaphragms can be given a high anduniform tension. 3y these tension devices the shape Ot the diaphragms ispreserved, and at need the same can be varied by operating the screws.

lis an insulator or support for the line-wire, consisting of a loop ot'spring-wire bent in an oval shape, with loop fi at the top for attachingto wire that attaches to pole and hook l and eye m On side, whereby itcan be easily hooked on the line-wire.

The air-space between the diaphragms acts as a damper to destroy thelateral or ringing vibrations. The resonant box and two diaphragms, withthis intervening cushion, forni a device which is sensitive and producesa clear and loud sound.

The insulator renders it unnecessary to cut the line-wire or to slip iton from the end, the loop being simply hooked on.

Vhat we claim isl. In a telephone, the combination of a box, having anopening and two parallel concaveconvex diaphragms, with air-chamberbetween extending across said opening.

2. In a telephone, the diaphragm, in combination with the tension-wiresand adjustingbars located within the box,and the wires connecting thediaphragm with the bars, whereby the movement of the latter controls theposition of the diaphragms.

3. An insulator consisting of a loop having an eye at one end and a hookand eye to the side.

In testimon y whereof weaflix our signatures in presence ot' twowitnesses.

JAMES R. HOLCOMB. JOHN D. HOLOOMB. CHARLES F. HOLOOMB.

Witnesses C. L. BROWN, W. H. CHAMEERLIN.

